/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.io;

import proguard.classfile.ClassConstants;

import java.io.IOException;
import java.util.Map;

/**
 * This DataEntryReader delegates to another DataEntryReader, renaming the data entries based on the given map. Entries
 * whose name does not appear in the map may be passed to an alternative DataEntryReader.
 *
 * @author Eric Lafortune
 */
public class RenamedDataEntryReader implements DataEntryReader {
    private final Map nameMap;
    private final DataEntryReader dataEntryReader;
    private final DataEntryReader missingDataEntryReader;

    /**
     * Creates a new RenamedDataEntryReader.
     * 
     * @param nameMap the map from old names to new names.
     * @param dataEntryReader the DataEntryReader to which renamed data entries will be passed.
     */
    public RenamedDataEntryReader(Map nameMap, DataEntryReader dataEntryReader) {
        this(nameMap, dataEntryReader, null);
    }

    /**
     * Creates a new RenamedDataEntryReader.
     * 
     * @param nameMap the map from old names to new names.
     * @param dataEntryReader the DataEntryReader to which renamed data entries will be passed.
     * @param missingDataEntryReader the optional DataEntryReader to which data entries that can't be renamed will be
     *        passed.
     */
    public RenamedDataEntryReader(Map nameMap, DataEntryReader dataEntryReader,
        DataEntryReader missingDataEntryReader) {
        this.nameMap = nameMap;
        this.dataEntryReader = dataEntryReader;
        this.missingDataEntryReader = missingDataEntryReader;
    }

    // Implementations for DataEntryReader.

    public void read(DataEntry dataEntry) throws IOException {
        String name = dataEntry.getName();

        // Add a directory separator if necessary.
        if (dataEntry.isDirectory() && name.length() > 0) {
            name += ClassConstants.PACKAGE_SEPARATOR;
        }

        String newName = (String)nameMap.get(name);
        if (newName != null) {
            // Remove the directory separator if necessary.
            if (dataEntry.isDirectory() && newName.length() > 0) {
                newName = newName.substring(0, newName.length() - 1);
            }

            dataEntryReader.read(new RenamedDataEntry(dataEntry, newName));
        } else if (missingDataEntryReader != null) {
            missingDataEntryReader.read(dataEntry);
        }
    }
}
